1. Field of the Invention
The present invention relates to an electronic appliance that is connected to a plurality of external appliances. More particularly, the present invention relates to an electronic appliance that is connected to a contents providing apparatus that provides contents.
2. Description of Related Art
Today, various kinds of recording medium are available, for example audio tapes, video tapes, CDs (compact discs), DVDs (digital versatile disks), MDs (minidisks), and hard disks, and these recording media are used to store audio and video contents. On the other hand, contents are provided for a general audience via various kinds of communication medium, for example terrestrial television and radio broadcasting, satellite broadcasting, cable television broadcasting, digital television broadcasting, and the Internet.
To cope with this, various kinds of contents providing apparatus are available, for example recording medium playback apparatuses for playing back various kinds of recording medium having contents as mentioned above recorded thereon, tuner apparatuses for receiving various broadcast signals, and network apparatuses connected to the Internet, and these apparatuses are connected to reproduction/output apparatuses provided with displays and speakers for reproducing and outputting audio and video. These contents providing apparatuses and reproduction/output apparatuses are typically accompanied with their respective remote control units for feeding them with operation commands.
Thus, when a contents providing apparatus and a reproduction/output apparatus, each accompanied with a remote control unit, are connected together, operating those apparatuses requires the user to communicate with them by using one remote control unit sometimes and the other remote control unit other times. If the contents providing apparatus and the reproduction/output apparatus are installed in remote places, for example in different rooms, the user monitoring by the side of the reproduction/output apparatus needs to move over to the place where the contents providing apparatus is installed to operate it. This is troublesome.
As a solution to this inconvenience, there has conventionally been proposed a centralized control system for controlling electronic appliances (see Japanese Patent Application Laid-Open No. H10-116058). In this system, control signals are transmitted to, among a plurality of electronic appliances connected together, only a particular electronic appliance from the remote control unit dedicated thereto, and doing so permits all the other connected electronic appliances to be operated. For example, assume that the particular electronic appliance is an AV amplifier, and a CD changer is connected as an electronic appliance to the AV amplifier. In this case, both the CD changer and the AV amplifier can be operated by the use of the remote control unit designed for and dedicated to the AV amplifier. Specifically, to operate the CD changer, an operation command therefor is transmitted to the AV amplifier from the remote control unit dedicated thereto. The AV amplifier then converts the received operation command into a control signal for operating the CD changer, and then transmits it to the CD changer, with the result that the operation of the CD changer is controlled in the desired manner.
There has also been proposed an electronic appliance that can readily recognize the kind of an external appliance connected thereto (see Japanese Patent Application Laid-Open No. H11-308538). This electronic appliance recognizes the kind of the external appliance by judging the signal corresponding to a particular operation that is transmitted from the remote control unit dedicated to that external appliance. Once the electronic appliance recognizes the kind of an external appliance in this way, when the electronic appliance thereafter receives a signal from the remote control unit dedicated to the external appliance, the electronic appliance recognizes it as a control signal for the external appliance, and then transmits the recognized control signal to the external appliance, with the result that the operation of the external appliance is controlled in the desired manner.
The centralized control system proposed in Japanese Patent Application Laid-Open No. H10-116058 mentioned above, however, has the following disadvantages. First, it cannot control the operation of the electronic appliances connected together by the use of any remote control unit other than that dedicated to a particular electronic appliance. For example, in a case where a contents providing apparatus is connected to a reproduction/output apparatus, the operation of the contents providing apparatus can only be controlled via the reproduction/output apparatus by the use of the remote control unit dedicated thereto. Thus, if this dedicated remote control unit becomes missing, it becomes impossible to perform remote control via the reproduction/output apparatus. Second, in a case where a plurality of electronic appliances of the same kind are connected together, an identical control signal is transmitted for a particular operation of any one of those electronic appliances. This makes it impossible to judge which electronic appliance to actually operate. For example, in a case where a plurality of contents providing apparatuses of the same kind are connected to a reproduction/output apparatus, an identical control signal is likely to be recognized by every one of those contents providing apparatuses of the same kind as one addressed thereto, with the result that all the contents providing apparatuses start to perform the operation specified by the control signal.
On the other hand, the electronic appliance proposed in Japanese Patent Application Laid-Open No. H11-308538 mentioned above has the following disadvantages. First, when a control signal is transmitted from a remote control unit, only such external appliances as are designed to work with this remote control unit can be operated; that is, no external appliances that are not designed to work with that remote control unit can be controlled. Second, in a case where a plurality of external appliances are connected together, selection among them is achieved by judging the remote control unit that is communicating with the electronic appliance. Thus, every time the electronic appliance to be operated is switched from one to another, the remote control unit used for that purpose needs to be switched from one to another. Third, which external appliance to actually operate is judged according to the kind of the remote control unit being used. Thus, in a case where a plurality of external appliances of the same kind are connected together, when the remote control unit of any one of those external appliances is used, a control signal transmitted therefrom is likely to be recognized by every one of those external appliances as one addressed thereto, with the result that all the external appliances start to perform the operation specified by the control signal.